Axon growth and Synapse formation Flashcards
What is determined by the frog experiment
Axons are capable of precise growth.
How do the axons and dendrites form?
They grow from the neuron’s soma.
Where do the filopodia and the growth cone localise?
At each growing tip of an axon.
How is the phenomena that the frog experiment (Sperry) explains called?
Chemoaffinity hypothesis-revised- growth cones seem to be influenced be a series of chemical and physical signals along the route.
Where does the neural plate form?
On the dorsal part of the embryo, on the ectodermal layer.
Cum se formeaza placa neuronala?
Formarea placii este indusa de semnale chimice dintr o zona de sub mesoderm.
Where does the neural proliferation happen?
In the ventricular zone, near to the center of the tube
How does the neural proliferation happen?
Chemical signals from the floor plate and the roof plate.
What are the two kinds of migration?
Radial and tangential
How do the cells communicate?
Through gap junctions, birdged by narrow tubes called connexins, exchanging cytoplasm.
What is fasiculation
The tendecy of the growing axons to follow the preestablished routes by the predecing axons( pioneer growth cones)
What is the topographic gradient hypothesis?
Growing axons are guided to their destinations by two intersecting signal gradients(anterior posterior, medial lateral)
What is synaptogenesis
The formation of new synapses.
What’s the relation between synaptogenesis and astrocytes?
Synaptogenesis depends on the presence of the glial cells, particularly astrocytes.
How do the astrocytes contribue to the synapse formation?
They provide cholesterol that the developing neurons need
